ART: Make InstructionSet an enum class and add kLast.

Adding InstructionSet::kLast shall make it easier to encode
the InstructionSet in fewer bits using BitField<>. However,
introducing `kLast` into the `art` namespace is not a good
idea, so we change the InstructionSet to an enum class.
This also uncovered a case of InstructionSet::kNone being
erroneously used instead of vixl32::Condition::None(), so
it's good to remove `kNone` from the `art` namespace.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: I6fa6168dfba4ed6da86d021a69c80224f09997a6

1 files changed, 4 insertions, 4 deletions

diff --git a/compiler/optimizing/instruction_simplifier_shared.cc b/compiler/optimizing/instruction_simplifier_shared.cc
index 1c13084a48..ccdcb3532d 100644
--- a/compiler/optimizing/instruction_simplifier_shared.cc
+++ b/compiler/optimizing/instruction_simplifier_shared.cc
@@ -90,13 +90,13 @@ bool TrySimpleMultiplyAccumulatePatterns(HMul* mul,
 bool TryCombineMultiplyAccumulate(HMul* mul, InstructionSet isa) {
   DataType::Type type = mul->GetType();
   switch (isa) {
-    case kArm:
-    case kThumb2:
+    case InstructionSet::kArm:
+    case InstructionSet::kThumb2:
       if (type != DataType::Type::kInt32) {
         return false;
       }
       break;
-    case kArm64:
+    case InstructionSet::kArm64:
       if (!DataType::IsIntOrLongType(type)) {
         return false;
       }
@@ -148,7 +148,7 @@ bool TryCombineMultiplyAccumulate(HMul* mul, InstructionSet isa) {
         mul->GetBlock()->RemoveInstruction(mul);
         return true;
       }
-    } else if (use->IsNeg() && isa != kArm) {
+    } else if (use->IsNeg() && isa != InstructionSet::kArm) {
       HMultiplyAccumulate* mulacc =
           new (allocator) HMultiplyAccumulate(type,
                                               HInstruction::kSub,